# WHATPORT(4242)

## NAME

port 4242 — OpenTSDB / Quassel core (unregistered convention) — A popular round-number port: OpenTSDB's metrics daemon and Quassel's IRC core both default here.

Protocol: TCP  
IANA registry

## DESCRIPTION

IANA has no individual entry for 4242 — it sits inside the 4200–4299 block registered as vrml-multi-use — so everything here is convention. OpenTSDB's time-series daemon leaves tsd.network.port required-but-empty in its source config and sets it to 4242 in the packaged one, and serves its HTTP API and metrics ingest there. Quassel's always-on IRC core also defaults to 4242 for its clients, and Code42's CrashPlan backup client used it as well. Fingerprint before assuming: an HTTP answer on /api/version is OpenTSDB, a binary handshake is more likely Quassel.

## EXPOSURE

**Expose with care.** Which occupant it is decides everything. OpenTSDB has no built-in authentication at all, so a public tsd is an open read/write metrics store and should never face the internet; a Quassel core is designed for remote clients and is reasonable to expose, but only with TLS and a strong password.

## CHECK

```sh
curl -s --max-time 5 http://TARGET:4242/api/version
```

## SEE ALSO

- source — [OpenTSDB/opentsdb — packaged opentsdb.conf, tsd.network.port = 4242](https://github.com/OpenTSDB/opentsdb/blob/master/build-aux/rpm/opentsdb.conf) (github.com)
- docs — [Quassel IRC — changing the core's default port 4242](https://quassel-irc.org/node/61) (quassel-irc.org)
- iana — [IANA port registry — 4200-4299 (vrml-multi-use)](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml?search=4242) (iana.org)

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HTML: <https://whatport.net/4242/> · JSON: <https://whatport.net/4242.json> · full dataset: <https://whatport.net/ports.json>